Search results
Results From The WOW.Com Content Network
For example, such a regulation might limit the concentration of NOx to 55 ppmv in a dry combustion exhaust gas corrected to 3 volume percent O 2. As another example, a regulation might limit the concentration of particulate matter to 0.1 grain per standard cubic foot (i.e., scf) of dry exhaust gas corrected to 12 volume percent CO 2.
This article presents methods for converting concentrations from ppmv to mg/m 3 (and vice versa) and for correcting the concentrations to the required reference conditions. All of the concentrations and concentration corrections in this article apply only to air and other gases. They are not applicable for liquids.
At 1 ppm the solution is a very pale yellow. As the concentration increases the colour becomes a more vibrant yellow, then orange, with the final 10,000 ppm a deep red colour. In science and engineering , the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities , e.g. mole fraction or ...
The concentrations of carbon dioxide in the atmosphere are expressed as parts per million by volume (abbreviated as ppmv, or ppm(v), or just ppm). To convert from the usual ppmv units to ppm mass (abbreviated as ppmm, or ppm(m)), multiply by the ratio of the molar mass of CO 2 to that of air, i.e. times 1.52 (44.01 divided by 28.96).
In environmental chemistry we make a distinction between parts per million {or billion, etc.} by *volume* vs. ppm by *weight*. For a dilute solution, such as NaCl in water, concentration is often expressed as weight of solute divided by mass of solution (typically assuming 1 g/mL for dilute water-based solutions) -- i.e., ppm by weight.
Count rate does not universally equate to dose rate, and there is no simple universal conversion factor. Any conversions are instrument-specific. Counts is the number of events detected, but dose rate relates to the amount of ionising energy deposited in the sensor of the radiation detector. The conversion calculation is dependent on the ...
Maximum concentration standard Carbon monoxide 8 hours 9 ppm Nitrogen dioxide 1 hour 0.12 ppm 1 year 0.03 ppm Ozone 1 hour 0.10 ppm 4 hours 0.08 ppm Sulfur dioxide 1 hour 0.20 ppm 1 day 0.08 ppm 1 year 0.02 ppm Lead 1 year 0.50 μg/m 3: PM 10 1 day 50 μg/m 3: 1 year 25 μg/m 3: PM 2.5 1 day 25 μg/m 3: 1 year 8 μg/m 3
where TDS is expressed in mg/L and EC is the electrical conductivity in microsiemens per centimeter at 25 °C. The conversion factor k e varies between 0.55 and 0.8. [5] Some TDS meters use an electrical conductivity measurement to the ppm using the above formula. Regarding units, 1 ppm indicates 1 mg of dissolved solids per 1,000 g of water. [6]